How Do Bank Closure Letters Work? It can be as simple as "we are closing your account as of X date.Want to close a bank account? You might need to submit a written request. No such account should ever include a State Federal ID number, nor the names of either the State of New York or a state agency in the title of the account. Complete required documentation: Depending on your bank, you may need to fill out a form, and in some cases this form must be notarized. This letter is to inform you I am closing my accounts at your bank. A letter of instruction is a document that lists all of your important financial account information in one place. A letter of instruction can complement an estate plan and provide your loved ones with additional details about your assets and wishes after death. Send account closure letter via email, link, or fax.